PRELIMINARIES. Motivation: Sensitivity and Large-Scale Systems. Nonlinear Solid Mechanics: Continuous and Semi-Discretized Formulation. Concepts of Sensitivity Analysis for Linear Systems.THE SENSITIVITY OF NONLINEAR SYSTEMS. The Basic Concepts of Nonlinear Quasi-Static Problems at Regular States. Inelastic Systems. Shape Sensitivity. Buckling and Post-Buckling. Nonlinear Dynamics. Metal Forming Using the Flow Approach. Nonlinear Thermal Systems. Appendices. References. Index. Glossary of Symbols.

Parameter Sensitivity in Nonlinear Mechanics: Theory and Finite Element Computations

Data-driven methods in structural health monitoring (SHM) is gaining popularity due to recent technological advancements in sensors, as well as high-speed internet and cloud-based computation. Since the introduction of deep learning (DL) in civil engineering, particularly in SHM, this emerging and promising tool has attracted significant attention among researchers. The main goal of this paper is to review the latest publications in SHM using emerging DL-based methods and provide readers with an overall understanding of various SHM applications. After a brief introduction, an overview of various DL methods (e.g., deep neural networks, transfer learning, etc.) is presented. The procedure and application of vibration-based, vision-based monitoring, along with some of the recent technologies used for SHM, such as sensors, unmanned aerial vehicles (UAVs), etc. are discussed. The review concludes with prospects and potential limitations of DL-based methods in SHM applications.

Data-Driven Structural Health Monitoring and Damage Detection through Deep Learning: State-of-the-Art Review.

https://cyberleninka.org/article/n/843987.pdf

OpenSeesPy: Python library for the OpenSees finite element framework

The particle finite element method (PFEM) is a powerful and robust numerical tool for the simulation of multi-physics problems in evolving domains. The PFEM exploits the Lagrangian framework to automatically identify and follow interfaces between different materials (e.g. fluid–fluid, fluid–solid or free surfaces). The method solves the governing equations with the standard finite element method and overcomes mesh distortion issues using a fast and efficient remeshing procedure. The flexibility and robustness of the method together with its capability for dealing with large topological variations of the computational domains, explain its success for solving a wide range of industrial and engineering problems. This paper provides an extended overview of the theory and applications of the method, giving the tools required to understand the PFEM from its basic ideas to the more advanced applications. Moreover, this work aims to confirm the flexibility and robustness of the PFEM for a broad range of engineering applications. Furthermore, presenting the advantages and disadvantages of the method, this overview can be the starting point for improvements of PFEM technology and for widening its application fields.

/pdf/a-state-of-the-art-review-of-the-particle-finite-element-4yttz7zq9k.pdf

A State of the Art Review of the Particle Finite Element Method (PFEM)

Summary
This paper presents a Lagrangian formulation of elastoviscoplasticity, on the basis of the particle finite element method, for progressive failure analysis of sensitive clays. The sensitive clay is represented by an elastoviscoplastic model that is a mixture of the Bingham model, for describing rheological behaviour, and the Tresca model with strain softening for capturing the progressive failure behaviour. The finite element formulation for the incremental elastoviscoplastic analysis is reformulated, through the application of the Hellinger–Reissner variational theorem, as an equivalent optimisation program that can be solved efficiently using modern algorithms such as the interior-point method. The recast formulation is then incorporated into the framework of the particle finite element method for investigating progressive failure problems related to sensitive clays, such as the collapse of a sensitive clay column and the retrogressive failure of a slope in sensitive clays, where extremely large deformation occurs. Copyright © 2017 John Wiley & Sons, Ltd.

/pdf/lagrangian-modelling-of-large-deformation-induced-by-yfoprmslsc.pdf

Lagrangian modelling of large deformation induced by progressive failure of sensitive clays with elastoviscoplasticity

Modeling fluid-structure interaction by the particle finite element method in OpenSees

The performance of bridges prone to tsunami hazards is critical to the resilience of coastal communities. An important component of resilience is the development of design guidelines, which requires simulating the hydrodynamic loads imparted on bridges by tsunami waves. To support such simulation efforts, data collected from wave flume experiments were used to validate the particle finite-element method (PFEM) implementation in OpenSees, which has been widely used for earthquake engineering simulation of bridges. The numerical results agree well with the experimental data, showing the potential use ofOpenSees for determining hydrodynamic loads on engineered structures. Given the wide-ranging earthquake engineering simulation capabilities ofOpenSees, these validations form a basis for simulating bridge responses to multihazard earthquake and tsunami scenarios. DOI: 10.1061/(ASCE)BE.1943-5592.0001221. This work is made available under the terms of the Creative Commons Attribution 4.0 International license, http://creativecommons.org/licenses/by/4.0/. Author keywords: Simulation; Tsunamis; Wave loads; Finite elements; Particle methods.

https://ascelibrary.org/doi/pdf/10.1061/%28ASCE%29BE.1943-5592.0001221

Validation of OpenSees for Tsunami Loading on Bridge Superstructures

SUMMARY

Numerical difficulties are present in the particle finite element method even though it has been shown to be a powerful and effective approach to simulating fluid-structure interaction. To overcome problems of mass loss on the free surface and the added-mass effect, an improved fractional step method (FSM) that handles added-mass terms in a mathematically exact way is developed. A further benefit is that no assumptions regarding the structural response are made in handling added-mass terms, thus it is straightforward to incorporate material nonlinearity in fluid-structure interaction (FSI) under this approach. Patch tests and comparisons with experimental data are presented in order to verify and validate the improved FSM for FSI applications. The computational cost of this approach is shown to be negligible compared with the other aspects of the FSM, particularly when the size of the structure and the fluid-structure interface is small relative to the volume of fluid. Copyright © 2014 John Wiley & Sons, Ltd.

Minjie Zhu

Papers

OpenSeesPy: Python library for the OpenSees finite element framework

Modeling fluid-structure interaction by the particle finite element method in OpenSees

Validation of OpenSees for Tsunami Loading on Bridge Superstructures

Improved fractional step method for simulating fluid‐structure interaction using the PFEM

Unified fractional step method for Lagrangian analysis of quasi-incompressible fluid and nonlinear structure interaction using the PFEM